Construction and characterization of novel dual stress-responsive bacterial biosensors

Robert J. Mitchell, Man Bock Gu

Research output: Contribution to journalArticlepeer-review

39 Citations (Scopus)


Using the genes for the green fluorescence protein and Xenorhabdus luminescens luciferase operon and the promoters for the recA and katG genes, two stress-responsive Escherichia coli biosensor strains have been constructed that can individually or concurrently respond to oxidative and genotoxic conditions. Strain DUO-1 carries the pRGDK1 plasmid, which has the recA::GFPuv4 and katG::luxCDABE fusion genes oriented divergently with each other, while in DUO-2, i.e., pRGDK2, they are in a tandem orientation, with the recA promoter showing run-though transcription of the katG::luxCDABE fusion. These two strains and their responses were characterized using several known hydroxyl radical-forming chemicals, e.g., hydrogen peroxide and cadmium chloride, along with some genotoxins, e.g., mitomycin C and methyl-N-nitro-N-nitrosoguanidine, and some general toxicants. Both strains showed an induction of green fluorescent protein (GFP) and bioluminescence when they experienced DNA and oxidative damage, respectively, while the tandem orientation of the two fusion genes within DUO-2 allowed it to also sensitively respond to genotoxins via the production of bioluminescence. However, the characteristics of DUO-2's bioluminescent response to each stress were easily distinguishable, making it useful for the detection of both stresses. Furthermore, tests with mixtures of chemicals showed that both DUO-1 and DUO-2 were responsive when chemicals causing oxidative or genotoxic stress were present as a single chemical or within complex chemical mixtures.

Original languageEnglish
Pages (from-to)977-985
Number of pages9
JournalBiosensors and Bioelectronics
Issue number9
Publication statusPublished - 2004 Apr 15
Externally publishedYes


  • Bacterial biosensor
  • Bioluminescence
  • Genotoxin
  • Green fluorescent protein
  • Oxidative damage
  • Stress

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry


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